Your guide to switching to solid cosmetics in 2025

Why switching to solid cosmetics is worthwhile

What are solid cosmetic products?

Solid cosmetics are an innovative product category in the cosmetics and personal care industry that combines functionality, sustainability, and ease of use in a unique way. Solid products differ fundamentally from liquid formulations because they contain no added water and therefore no preservatives.

Unlike conventional bottled products, solid cosmetics do not require additional preservatives because they do not contain any water. They are usually made from high-quality natural oils, butters, waxes, and nourishing ingredients that are processed into a compact, solid structure. They are applied directly to the skin or hair, where the warmth and movement of the body make the product smooth.

In practice, this product group includes a wide range of care products for different areas of the body and applications. These include not only classic solid soap bars, but also innovative developments such as solid shampoos and conditioners, solid facial cleansers, compact body lotions, and even solid face masks. Each of these products is designed to simplify care while contributing to environmental protection.

In this article, we will focus on solid shampoos and shower gels.

What is the difference between soap and a bar of soap?

A bar of soap or solid (also called “syndet”) and soap look very similar. In fact, however, these two solid care products have very little in common.

While soaps, like syndets, are made from natural fats (e.g., olive oil, cocoa butter, shea butter), the production of soap also requires a lye, usually sodium hydroxide or potassium hydroxide. Since this is alkaline, the soap also becomes alkaline. This is detrimental to the pH value of the skin, as the skin's acidic protective film is neutralized and thus loses its protective effect. The result: the skin can react more sensitively to bacteria and fungi. However, the acid mantle usually regenerates within a few hours. Soaps are also usually poured.

In contrast, syndets also rely on high-quality, natural oils. However, instead of lye, surfactants are used, which can be adjusted in the formulation so that the soap bars are pH-neutral and do not attack the skin's natural acid protection. Syndets are usually pressed into a specific shape under pressure, compacting the high-quality ingredients—this is how our solids get their iconic shape. 1,2

Why solid cosmetics? Are solid products better than liquid ones?

We have already mentioned some of the advantages of solid care products above. For example, they usually do not contain preservatives because they are water-free. Or that they take up much less space and fit into a folding box instead of having to be filled into a large plastic bottle.

Environmental protection: Less plastic, more responsibility

The traditional cosmetics industry produces millions of tons of plastic waste every year. Solid cosmetic products are a response to this level of consumption, as they are almost exclusively packaged in folding cartons. Without plastic packaging and with minimal packaging, they drastically reduce their ecological footprint and prevent plastic from becoming waste in the first place.

Water-free: significant CO2 savings

The compressed form and water-free formula of solid care products have another advantage. Due to the lower weight and smaller dimensions of the packaging, more products fit into a truck. While 10 trucks are needed to transport classic liquid products to the drugstore, the same amount of solid products fits into one truck. This is not only efficient, but also saves a lot of CO2 during transport.

Travel and everyday life: small size and low weight

There are no liquid restrictions when traveling and no leaked products in your toiletries bag with solid care products! Because they are:

• hand luggage-friendly
• leak-proof
• easy to transport
• space-saving.

 

Purity of Ingredients

Since solid cosmetic products are water-free, they can:

• do without aggressive preservatives
• be more concentrated and economical.

Cost-effectiveness: more care for the same price

Thanks to their compact form and concentrated ingredients, solid cosmetic products often last significantly longer than conventional products. Depending on usage, a solid product can last for weeks or even months, making it not only environmentally friendly but often more cost-effective as well. Of course, in addition to the amount used, proper storage after use is also important. We will discuss this further below.


How are solid shampoos and body wash bars produced?

As mentioned above, solid soap bars are pressed. However, this final step in the manufacturing process is preceded by many other steps:

Creating a formula:

The first step is to develop a formula which, similar to a recipe for cooking or baking, defines and specifies the ingredients of the finished product and the steps required to manufacture it.

Selection of high-quality raw materials

High-quality raw materials are selected and purchased based on this recipe.

Mixing

The raw materials are mixed to achieve the most uniform distribution possible of oils, detergents, fragrances, and additives (such as keratin).

Production

After mixing, the soap bars are pressed into the desired shape under high pressure. This is usually done with the help of hydraulic presses, which compress the ingredients under several tons of pressure. The compressed shape achieved in this way ensures that the solid remains dimensionally stable, but also ensures yield. This is because the pressure compresses the soap bars so that more mass is contained in the same area.

Packaging and transport

The finished solids are packed in folding boxes and prepared for transport to drugstores, grocery stores, or online shops. Due to their small size (our solid folding boxes are just as big as a regular notepad! Okay, admittedly, they are a little thicker, of course), transport is very efficient and saves CO2 compared to liquid products.



How are solid products stored correctly?

Many people are familiar with this scenario: the shower shelf is full of bottles, they are scattered everywhere, stacked on top of each other, at least one has already leaked, and the whole shelf is covered in shampoo or shower gel.


The correct storage of solid soap bars, on the other hand, is just as minimalist as the soap bar itself. We recommend storing our solids in such a way that they can drain and dry.
This is easiest with the solid wall mount made from Ocean Bound Plastic, which is specially optimized for the solid form but is also compatible with most other soap bars. The mount is attached to the shower without drilling (preferably not under the shower head) and holds your favorite solid.

If you are traveling or the wall mount does not fit in your shower, we recommend the Solid Box. You can place your solid soap in it to dry. When closed, the box is leak-proof (so your suitcase, gym bag, or other luggage stays dry, and you no longer have to pack your toiletries bag in a plastic bag 😉).



How long do solid shampoos and shower gels last?

There is no general answer to this question; it depends entirely on individual consumption. Solid shampoo naturally does not last as long on longer hair as it does on shorter hair. Utopia writes: “By the way: the slightly higher price compared to classic shampoos should not deter you. According to Öko-Test, solid shampoos can replace two 200-milliliter bottles of shampoo.”



Can you make solid shampoo and shower gel yourself?

The answer is a resounding yes! All you need is surfactants, cocoa or shea butter, starch, essential oils as desired, and an ovenproof mold. Please be sure to wear a face mask, as the surfactants can produce a lot of dust.





Sources:

1 https://www.test.de/Duschbaeder-Die-besten-fuer-empfindliche-Haut-1371672-1371657/

2 https://utopia.de/ratgeber/syndets-sind-die-tenside-besser-als-seife_201970/

3 https://utopia.de/echte-alternative-oeko-test-festes-shampoo-sehr-gut-wenige-ausnahmen_566413/